What is the scariest science fiction or fantasy film of all time? Which movies stand above the rest of all horror movies as the most terrifying?

The staff at io9 has painstakingly selected the best of the best, and compiled our ultimate list of the scariest movies of all time. Yesterday you saw the first 20 out of the 50, today, check out numbers 21 through 30...

30. Suspiria (1977)What: An American ballet student moves to Munich to attend a fancy pants ballet. After countless murders and plenty of blood she discovers that the staff of the school are actually a coven of witches.Why: Such beautiful gore, and creative deaths. Dario Argento changed the way we looked at murder, it could be gorgeous but still tremendously unsettling.Scariest Scene: Death by razor wire.

29. Night of the Living Dead (1968)What: The movie that launched the undead craze, directed by George A. Romero. Five people are trapped in a farmhouse while the dead walk the Earth and try and rip them apart. Note: they weren't called zombies yet in this picture, rather ghouls.Why: THE DEAD WERE WALKING THE EARTH.Scariest Scene: The cemetery scene.

28. Nosferatu (1922)What: A complete ripoff of Bram Stoker's Dracula, because they just couldn't afford to pay for the very popular book rights.Why:Max Schreck who plays the vampire Count Orlok basically transforms himself into a beast. It's so uncomfortable watching this movie today, we can't even imagine what this did to folks when it opened.Scariest Scene: The shadow that grabs your heart and twists your body!

27. The Hills Have Eyes (1977)What: A family is attacked by a wild band of mutant cannibals.Why: We have admit, the remake almost took the original's place on this list. But, while it is super scary, it doesn't have the horrifying Michael Berryman. Plus the original shocked audiences with its unforgiving death toll. It broke all the rules — not even grandma and the dogs were safe.Scariest Scene: While the rape/fire execution moment is infamous, we were shocked to our core when Mars ripped off the head a bird and drank its guts.

26. Rec (2007)What: A camera crew is quarantined inside an apartment complex while the tenants turn into zombies.Why: Just good old fashioned "help we're trapped in an apartment with people that want to eat us"!Scariest Scene:While many folks think the last five seconds of the film (where the girl is dragged off) is the scariest moment. They are wrong. The best part is the one-two punch of the first reveal of the evil zombie, followed by the stumbling whitey tighty zombie the quarantined news crew finds themselves trapped in an attack with (don't make any sudden noises!).

25. Signs (2002)What: Aliens are secretly invading the Earth, and one of their contact points is Mel Gibson's farm.Why: Before M. Night Shyamalan became a directorial disaster, he really knew how to scare folks without doing much at all. A hand in the corn field, an outline on the roof, it drove the audience mad with fear.Scariest Scene: The birthday party.

24. The Omen (1976)What: A couple adopts the Antichrist.Why: The music, the mood, the incredibly slow burn. Richard Donner made a very creepy movie about a little boy with a lot of evil potential — hell, he even made you fear a little kid on a tricycle.Scariest Scene: "It's all for you Damien, it's all for you!"

23. The Last Exorcism (2010)What:Lost soul Reverend Cotton Marcus spends his days "exorcising" fake demons. But the truth of the matter is, he's a con man who's lost faith (haven't they all). But that all changes after he meets the troubled Nell (played by the brilliant Ashley Bell).Why: We thought found footage horror was dead, until this film came along. It's simple, but it just works. Plus the characters attempt to make intelligent decisions, right up until the very end. They keep assuming the little girl isn't possessed, she's clearly getting abused by her father, so they should call the police.Scariest Scene: The second exorcism which takes place in the barn. Listen for all the bone snaps!

22. Pet Sematary (1989)What A young couple discovers an magic burial ground that brings the dead back to life, but they come back wrong. But wrong doesn't seem so bad after their child, Gage, is killed by a truck.Why "Sometimes dead is better," is just a wonderful line. Plus undead Gage is two feet of absolute horror. Mary Lambert pulled out all the horrifying stops to scare you with this flick, hell she even dressed Gage up in the creepy child top hat from the horrible painting.Scariest Scene Gage slices Jud's Achilles tendon.

21. Jacob's Ladder (1990)What Tim Robbins plays a Vietnam Vet who starts experiencing horrible hallucinations. Split between multiple realities, the audience never knows who or what to believe. Is this Vet a victim of horrible drug tests dolled out during the war, or is he just in hell?Why Lots and lots of confusion — you never know what's going on, and Robbins totally sells the terrible darkness leaking out of his brain. It's a smorgasbord of horrible emotions from shame, fear, dread, depression.Scariest Scene When the main character is being wheeled into a mental ward, things start going horribly wrong, but ever so slowly at first.